[PATCH v2 04/21] ARM: implement elf_apply_relocations() for ELF relocation support

[Sascha Hauer]

Implement architecture-specific ELF relocation handlers for ARM32 and ARM64.
The implementation reuses the existing relocate_image().

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Co-Authored-By: Claude Sonnet 4.5 <noreply at anthropic.com>
---
 arch/arm/include/asm/elf.h |  7 +++++++
 arch/arm/lib32/reloc.c     | 23 +++++++++++++++++++++++
 arch/arm/lib64/reloc.c     | 25 +++++++++++++++++++++++--
 3 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 0b4704a4a5615e648f67705ad9daf8dea9f41bab..630c85f2b421cba7e37ea7147c047be948ecdc7e 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -36,6 +36,13 @@ typedef struct user_fp elf_fpregset_t;
 #define R_ARM_THM_CALL		10
 #define R_ARM_THM_JUMP24	30
 
+/* Additional relocation types for dynamic linking */
+#define R_ARM_RELATIVE		23
+
+#define R_AARCH64_NONE		0
+#define R_AARCH64_ABS64		257
+#define R_AARCH64_RELATIVE	1027
+
 /*
  * These are used to set parameters in the core dumps.
  */
diff --git a/arch/arm/lib32/reloc.c b/arch/arm/lib32/reloc.c
index 378ba95b2ffd455436e704a803f5448fc2c2b18c..19a10ce7e7e637b8dbf7f71db3d97dfc0b215139 100644
--- a/arch/arm/lib32/reloc.c
+++ b/arch/arm/lib32/reloc.c
@@ -6,6 +6,7 @@
 #include <barebox.h>
 #include <elf.h>
 #include <debug_ll.h>
+#include <linux/printk.h>
 #include <asm/reloc.h>
 
 #define R_ARM_RELATIVE 23
@@ -54,3 +55,25 @@ void __prereloc relocate_image(unsigned long offset,
 	if (dynend)
 		__memset(dynsym, 0, (unsigned long)dynend - (unsigned long)dynsym);
 }
+
+/*
+ * Apply ARM32 ELF relocations
+ */
+int elf_apply_relocations(struct elf_image *elf, const void *dyn_seg)
+{
+	Elf32_Rel *rel;
+	void *rel_ptr;
+	u64 relsz;
+	phys_addr_t base = (phys_addr_t)elf->reloc_offset;
+	int ret;
+
+	ret = elf_parse_dynamic_section_rel(elf, dyn_seg, &rel_ptr, &relsz);
+	if (ret)
+		return ret;
+
+	rel = (Elf32_Rel *)rel_ptr;
+
+	relocate_image(base, rel, (void *)rel + relsz, NULL, NULL);
+
+	return 0;
+}
diff --git a/arch/arm/lib64/reloc.c b/arch/arm/lib64/reloc.c
index 2288f9e2e336887c5edfbf6b080f487394754113..50bd0b88fae0a59a6a86a84c1df0743ac158e06c 100644
--- a/arch/arm/lib64/reloc.c
+++ b/arch/arm/lib64/reloc.c
@@ -7,8 +7,7 @@
 #include <elf.h>
 #include <debug_ll.h>
 #include <asm/reloc.h>
-
-#define R_AARCH64_RELATIVE 1027
+#include <linux/printk.h>
 
 /*
  * relocate binary to the currently running address
@@ -45,3 +44,25 @@ void __prereloc relocate_image(unsigned long offset,
 		dstart += sizeof(*rel);
 	}
 }
+
+/*
+ * Apply ARM64 ELF relocations
+ */
+int elf_apply_relocations(struct elf_image *elf, const void *dyn_seg)
+{
+	Elf64_Rela *rela;
+	void *rel_ptr;
+	u64 relasz;
+	phys_addr_t base = (phys_addr_t)elf->reloc_offset;
+	int ret;
+
+	ret = elf_parse_dynamic_section_rela(elf, dyn_seg, &rel_ptr, &relasz);
+	if (ret)
+		return ret;
+
+	rela = (Elf64_Rela *)rel_ptr;
+
+	relocate_image(base, rela, (void *)rela + relasz, NULL, NULL);
+
+	return 0;
+}

-- 
2.47.3